reading comprehension - Subject confusion or mistranslation of 無難

A scientist is investigating a mysterious hole in the ground. His experiments have failed and I think he's a bit sulky. He then says:

「埋めてしまいなさい」
Fill it in.

Then the narration goes:

わからないことは、なくしてしまうのが無難だった。

My literal translation of this is "It was safe to get rid of something he didn't understand.", but that doesn't make much sense at all.

First of all I'm unsure of the subject of わかる. Is it the scientist or is or is it a generic "things one doesn't understand"?

Is this statement the narrator's belief, the scientists belief, or what the narrator thought the scientists would think?

With any combination of the above thoughts I still can't make a sentence that really seems to fit the context. Maybe I've translated 無難 wrongly?

Such a simple sentence, but I'm so confused.

Answer

I think the most natural sentence in this context would be:

わからないものは、なかったことにしてしまうのが無難だった

This means "The low-risk choice here was to pretend this mysterious thing never existed".

This is a bit different from

わからないことは、なくしてしまうのが無難だった。

First, the use of こと rather than もの means the author is including related things to the hole (it's a bit like home vs. house). They are still talking about the hole, but not only about the physical hole.

Second, they use なくしてしまう instead of なかったことにしてしまう. The difference is the former means "eliminate the thing", whereas the latter means "pretend it never existed". I guess it depends whether you think a hole can be eliminated completely by filling it in, or it's just hidden from view.
My guess is the author uses the former because the scientists' desire is to "kill" the hole - eliminate it. And they think they can do that by filling it in. I'm guessing the story goes, "scientists go home thinking they have successfully eliminated the hole and any related danger or creature or what have you, but it turns out filling the hole doesn't eliminate the hole at all".

This storyline is also strongly suggested by the use of 無難 because it's often used to mean "A low-risk choice that turns out to be wrong (the actor should have confronted the problem rather than taking the easy way out)".

As to whose belief it is, I think it's describing the scientists' belief.